RESPIRATORY SYSTEM HISTOLOGY

• BY • Trachea • Dr Navneet Kumar • Bronchus • Professor Anatomy -Primary bronchus • KGMU LKO -Secondary bronchus -Tertiary bronchus • Bronchiole • Lung

Dr Naveet Kumar Professor Anatomy KGMU LKO • RESPIRATORY SYSTEM HISTOLOGY BY Dr Navneet Kumar Professor Anatomy KGMU LKO

Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Trachea

• Mucosa -Epithelium -Lamina propria • Sub mucosa • Cartilage &muscle layer • Adventitia

Dr Naveet Kumar Professor Anatomy KGMU LKO Trachea Mucosa • Epithelium -Pseudo stratified ciliated columnar/ Respiratory epithelium Cells-Ciliated columnar cells - Goblet cells -Brush cells - Basal cells -Granule (kulchitsky) cells -Clara cells( bronchiolar cells) surfactant secretion • Lamina propria - Elastic fibre, Lymphocyte, Mast cells, Blood vessels Dr Naveet Kumar Professor Anatomy KGMU LKO Trachea

• Sub mucosa- • Loose connective tissue • Tracheal glands-Mixed (serous &mucus) glands • Cartilage &smooth muscle layer- • ”C” Shaped hyaline cartilage • Ends of cartilage connected by smooth muscles • Adventitia-fibro elastic tissue

Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Bronchus

• Principal bronchus -same as trachea • Secondary bronchus -Irregular hyaline cartilage -Pseudo stratified ciliated columnar • Tertiary bronchus -Columnar epithelium -Patches of cartilage

Dr Naveet Kumar Professor Anatomy KGMU LKO Bronchiole

• Terminal bronchiole -Columnar epithelium -No cartilage but smooth muscle -Clara cells present • Respiratory bronchiole -Cuboidal epithelium -No mucous gland

Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Respiratory Trachea Bronchus Tertiary bronchus Bronchiole bronchiole Epithelium Pseudostra  Columnar  Cuboidal tified Goblet cells +++ ++ ++ + Absent

Clara cells Absent Absent Absent + + Muscularis Absent + ++ +++ +++ mucosae Mucous glands +++ ++ + Absent Absent

Cartilage +++ ++ + Absent Absent

Alveoli Absent Absent Absent Absent +

Dr Naveet Kumar Professor Anatomy KGMU LKO Lung 1-Bronchus and bronchioles are present 2-Alveolar duct and alveoli- -Simple squamous epithelium Type 1 Pneumocytes(97% -Blood Air barrier Type2 Pneumocytes(2%) - pulmonary surfactant - lamellar bodies Type3Pneumocytes (brush cells) -Macrophages or Dust cells (Heart failure cells), 3-Inter alveolar septa & Supportive tissue Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO Dr Naveet Kumar Professor Anatomy KGMU LKO